For manufacturing and marketing reasons, compact discs carry digital data on only one of their faces. To permit easy identification of the face of the compact disc carrying the digital data, one system involves a printed label affixed to the opposite face of the disc which is free of such data.
Such means of identification is not altogether satisfactory since it requires a degree of attention by the user, which is not desirable, e.g., in the case of apparatus used in motor cars, and it also involves a danger of being misinterpreted since, generally, in the past, all disc records have carried a label on each recorded face.